A third type of spontaneous DNA damage that occurs frequently is damage to the bases by free radicals of oxygen. These arise in cells as a result of oxidative metabolism and also are formed by physical agents such as radiation.. Base pair (nucleotide pair) substitutions. These are of two types: transitions (purine to purine or pyrimidine to pyrimidine) and transversions (purine to pyrimidine or pyrimidine to purine). We break these down into the two categories because they can occur in different ways.
What happens if your flight is cancelled. In the unfortunate event that your flight is cancelled you can transfer to another easyJet flight for free or if youâd prefer you can get a full refund. You can do this quickly and easily in three ways online: simply log onto EasyJet.com/ (insert your flight number).
If you cancel or change your itinerary less than three hours before your scheduled flight, you will lose the entire ticket value, according to American Airlines.The same rule applies to non-refundable tickets.f you think your flight plans might change, buy a refundable ticket or purchase travel protection insurance, according to the American Airlines website. If airline personnel changes or cancels your planned flight due to unforeseen circumstances, they will first try to place you on another flight.